<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>学生管理系统（正在学习版）</title>
</head>
<body>
    班级列表
    {% for grade in grades %}
        <div>
            {{grade.grade_name}} - {{grade.grade_number}}
        </div>
    {% endfor %}
</body>
</html>